Palm oil is extracted by removing the seeds through the steam process. Herein, after the seeds are removed, lots of by-products are generated, which called empty fruit bunch (EFB), and the one generated from the seeds is called palm fiber (PF).
Up to now, since there has been a difficulty in processing these substances, the substances have been generally used as compost or fuel for producing the steam. However, there are too many by-products generated, and in order to use the by-products as compost or fuel, a space for storing the by-products is required. Further, as a given decay period is needed, a large space and time are additionally required, and lots of costs are spent for conveying it. For these reasons, there has been a difficulty in utilizing the by-products.
In particular, severer methods of utilizing the by-products as new renewable energy have been studied; however, there are many problems that the by-products contain too much water to be used as fuel, so the low-heating value is low, and thus, lots of the by-products are needed in order to incinerate them, which makes it difficult to put enough expenses for managing the by-products.
For the technique for processing palm oil mill waste, “Method for Preparing Biofertilizer Using Palm Oil Mill Wastage” (Korean Patent No. 10-0938490; Patent Literature 1) introduces a process of carbonizing a kernel shell, incinerating EFB, treating palm oil mill effluent (POME) with micro air bubbles and filtering the treated POME to obtain decanter cake, mixing them, and maturing the mixture to produce a biofertilizer.
However, the above technique has a problem that the consumption of energy sources occurs since EFB is carbonized and incinerated.
As another technique relating to a method of utilizing waste in the palm oil mill process, “Treatment Equipment Using Palm By-Products and Palm Oil Mill Effluent which is Finally Discharged in the Palm Oil Producing Process and a Method thereof” (Korean Patent No. 10-1265740; Patent Literature 2) which was filed by the present applicant and patented, provides the technology for processing palm oil decanter cake (PODC) and palm kernel cake (PKC) together with palm oil mill effluent (POME) so that the final effluent and palm by-products can be used as energy sources, feed resources, etc.
However, Patent Document 2, which relates to the integral processing method, is suitable for the treatment of POME, PODC or PKC, but has a problem that the method cannot be used for the treatment of an empty fruit bunch (EFB) or palm fiber (PF).
So far, the empty fruit bunch (EFB) or palm fiber (PF) have been used as fuel, and recently, they have been used for producing paper in the paper industry. However, such method has a problem that a huge amount of waste water is generated, which leads to lots of costs to be spent for processing the waste water and low economic efficiency.
Other than the above, various methods such as producing a board or producing fuel by producing a compressed pellet have been developed, but the methods have not been generalized due to their low economic efficiency and the complex processing process.
In particular, since the palm fiber (PF) is voluminous and contains a large content of poly phenol, the availability is greatly reduced, and the decay is fast. For this reason, it was difficult to utilize PF efficiently.
In addition, the empty fruit bunch and the palm fiber can be used as renewable energy by drying and pulverizing EFB and PF and compressing them to be pelletized. However, the cost for producing it is greatly increased as the amount of electricity used is increased and the amount of drying is introduced, etc., and thus the effectiveness becomes greatly reduced.
As such, in the palm industry, the treatment of the empty fruit bunch and the palm fiber remains as the most difficult problem in processing waste.
However, while the empty fruit bunch and the palm fiber have a disadvantage that they contain a large content of poly phenol (Lignin), they also have an advantage that they contain a large content of fibers and some of them contain oils, so if they are processed and used efficiently, they can be utilized as good feed materials with the greatly increased usability.
Thus, the effective treatment of the empty fruit bunch and the palm fiber has a significant meaning in the palm industry, and it is an important task to develop a continuous and economical method which can maintain the utilization stable.